Investments (Details 2) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012
Carrying Value [Member]
Summary of the cost or amortized cost and fair value of investments in fixed maturity securities, classified as held-to-maturity, by contractual maturity
Less than one year, Carrying Value	$ 85,230
One to five years, Carrying Value	165,923
Five to ten years, Carrying Value	133,106
More than ten years, Carrying Value	141,097
Total, Carrying Value	620,682
Carrying Value [Member] \| U.S. agency-based mortgage-backed securities [Member]
Summary of the cost or amortized cost and fair value of investments in fixed maturity securities, classified as held-to-maturity, by contractual maturity
Held-to-maturity, Carrying Value	39,013
Carrying Value [Member] \| Asset-backed securities [Member]
Summary of the cost or amortized cost and fair value of investments in fixed maturity securities, classified as held-to-maturity, by contractual maturity
Held-to-maturity, Carrying Value	4,773
Carrying Value [Member] \| Commercial mortgage-backed securities [Member]
Summary of the cost or amortized cost and fair value of investments in fixed maturity securities, classified as held-to-maturity, by contractual maturity
Held-to-maturity, Carrying Value	51,540
Fair Value [Member]
Summary of the cost or amortized cost and fair value of investments in fixed maturity securities, classified as held-to-maturity, by contractual maturity
Less than one year, Fair Value	85,833
One to five years, Fair Value	175,132
Five to ten years, Fair Value	147,163
More than ten years, Fair Value	150,767
Total, Fair Value	662,917
Fair Value [Member] \| U.S. agency-based mortgage-backed securities [Member]
Summary of the cost or amortized cost and fair value of investments in fixed maturity securities, classified as held-to-maturity, by contractual maturity
Held-to-maturity, Fair Value	42,744
Fair Value [Member] \| Asset-backed securities [Member]
Summary of the cost or amortized cost and fair value of investments in fixed maturity securities, classified as held-to-maturity, by contractual maturity
Held-to-maturity, Fair Value	4,154
Fair Value [Member] \| Commercial mortgage-backed securities [Member]
Summary of the cost or amortized cost and fair value of investments in fixed maturity securities, classified as held-to-maturity, by contractual maturity
Held-to-maturity, Fair Value	$ 57,124

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Amount of held-to-maturity debt securities at fair value maturing in the sixth fiscal year through the tenth fiscal year following the latest fiscal year.

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Amount of held-to-maturity debt securities at fair value maturing in the second fiscal year through the fifth fiscal year following the latest fiscal year.

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Amount of held-to-maturity debt securities at fair value that do not have a single maturity date and which the entity has decided to disclose separately rather than allocating the fair value over several maturity groupings.

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